Question

-What is the pH of a solution with [H₃O⁺] = (3.70x10^-5)?

- What is the pH of a solution with [OH^-] = (2.30x10^-8)?

- What type of pH should an aqueous solution of KF have?

- When HCl is added to a buffer solution composed of NaF and HF, what will react with the hydrochoric acid, and what product will be made?

Answer 1

(a)given [H3O+] =3.70*10^(-5)

as pH =-log[H3O+] =-log(3.70*10^(-5))=4.43

(b)given [OH-] =2.3*10^(-8)

as pOH =-log[OH-] =-log(2.3*10^(-8)) =7.64

as we know pH +pOH =14

pH =14-pOH =14-7.64 =6.36

(c)KF is salt of weak acid HF and strong base KOH.

So this salt is basic in nature.

So its pH >7

(d)we have a buffer of HF and NaF.

when HCl is added to the buffer, then it will react with F-

F- + HCl - - - >HF +Cl-

HF will form in the reaction.

actually reaction takes place in this way

F- +H3O+ - - - >HF +H2O

so HF will form in product.

comment if any issue.

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